Finaly got car all put bakc together!!

[Hesh724]

Runs great, spins all 4 tires like nothin. but I just got a new upgraded eprom and ISC and idle goes up and down by about 300 rpm? I think i hear a vacume leak but cant find it. any ideas could the new boostguage or intake or anything like that cause this.

 

[GRAVEDIGGER]

Have you done a boost leak test to help find your vacuum leak? If you find that leak you're hearing your problem will most likely be solved.

 

[Hesh724]

cool so i will rule out the ecu, tps, isc, since they are brand new.but the Mass air is iffy. also will a boost leak detector test all the little vacume lines like the ones that go into the back of the intake manifold i have a magnus and all the line hookups are in the back in a row and some feel like they could be loose. but i cant afford hose clamps right now !

 

[GRAVEDIGGER]

Yes, definitely concentrate on finding your leaks/sort out the mess of hoses and nipples ( that sounded funny) and you should be good to go. With any leaks present you are going to have a hard time holding a steady idle. Good luck my friend.

 

[Hesh724]

hoses and nipples but ya i found instructions for a homemade leak detector the only problem is my compressor is very small will 2gal 150 psi i know the presure will be ok but will the volume be enough just curious if i can do that right now before i go to work?

I just noticed a 3/4 inch hair crack on the dead top flat part of the exchaust manifold i can see the air coming out now that it is cold. i bet thats my idle problem?! im goin to grind out the crack and weld it up if thats it just so i dont have to wait on a nother.

 

[Hesh724]

New tps, isc, checked biss screw, coolant temp sensor, sprayed choke cleaner all over intake piping including throttle body and intake. Couldnt spary bottom of intake very well. i may be hoping but it seem like when i sprayed all over the top of the intake it did change alittle it went slower for a little bit i guess till the cleaner evaporated then sped back up, when i have the time in the next couple of days i will remove the intake and check all that. but will thet crack in my exhuaust mani cause what i am experienceing? no mechanic around here will touch my car and i am no expert . also boost leak detectors will only check inter cooler piping not like the vacume lines and the intake mani right? oh but i am planning on doing a proper leak test just havent bought the 9$ worth of stuff it takes to make one .

 

[rlacasse1]

What rpm is the car running at. Mine did the same thing, it would bounce around between 1200-1700rpm. So i idled it down to 800rpm and it quit bouncing around. Now when i let off the gas or it idles it goes straight to 800rpm and stays there.

 

[Hesh724]

it becomes less when it is warm. i have a nice size leak where the 3" down pipe to the 2.5 exuast pipe at the cat, also a very small hair crack on the top of my exhaust mani where they all meet does not let alot of air out yet. just got a coolant temp sensor and i think the wire is broke or i have it backwards or something cause my rad fans dont turn on either. this car is kicking my A$$. i exept for a proper boost leak test i have done everything parts wise.